Ever hear a banging noise in your water pipes when someone shuts off a faucet? That bothersome noise is called water hammer. Water hammer is the sound of moving water being suddenly stopped cold by the closing of a valve. Water Hammer Arrestors are used in commercial and industrial applications to control water pressure shock and prevent water hammer conditions. They are also used in residential applications such as installing one to stop the water pipes from banging in your floor or ceiling. Consider Water hammer arrestors from PPP, Sioux Chief and Watts.